1. Field of the Invention
The subject invention generally relates to a shifter assembly for providing mechanical actuation to a transmission of a vehicle by movement of a control cable and for providing electronic actuation to the transmission of the vehicle and a method of operating the shifter assembly.
2. Description of Related Art
In practically every vehicle today, a shifter is utilized to control the transmission of a vehicle. Some shifters mechanically actuate the transmission by movement of a mechanical linkage. For shifters which mechanically actuate the transmission, a driver generally moves a lever which in turn pushes or pulls the mechanical linkage thereby transmitting load to actuate the transmission.
Alternatively, other shifters electronically actuate the transmission. For shifters which electronically actuate the transmission, movement of the lever is electronically sensed. That is, a relative position of the lever is sensed by the shifter and an electronic signal is generated corresponding to the relative position of the lever. A control unit receives and processes the electronic signal and commands the transmission to actuate into a gear position corresponding to the relative position of the lever sensed by the shifter. However, having electronic shifting as the sole means of shifting the transmission is expensive because of the need for relatively expensive electronic components required to achieve performance comparable to shifters which are entirely dependent on mechanical shifting. In addition, the shifter is entirely dependent on electronic shifting and therefore cannot change gears of the transmission during a power failure of the vehicle.
Yet other shifters are capable of providing mechanical actuation as well as electronic actuation to the transmission. That is, such shifters mechanically actuate the transmission in specific gears, and electronically actuate the transmission in the remaining gears. These shifters generally have mechanical components to mechanically actuate the transmission. However, these shifters neither provide a robust structure nor method to prevent the mechanical components from unexpectedly moving out of position without the intent of the driver of the vehicle when the shifter is electronically actuating. As a result, there is an increased possibility that the transmission will be damaged. Further, U.S. Pat. No. 6,382,046 to Wang discloses a shifter capable of providing mechanical actuation as well as electronic actuation to the transmission. The shifter includes a cable block lever and a cable attachment bracket which pivot to mechanically actuate the transmission. However, the cable block lever may only indirectly urge the cable attachment bracket to pivot. That is, the cable block lever is fixed to the cable attachment bracket and must press against a wall of the shifter in order to create leverage to force the cable attachment bracket to pivot.
Therefore, there remains an opportunity to develop a shifter that provides both mechanical and electronic actuation to a transmission by utilizing a cable block lever and a cable attachment bracket being separated from each other such that the cable block lever itself urges the cable attachment bracket to pivot in order to provide mechanical actuation. In addition, there remains an opportunity to develop a shifter with the cable block lever itself preventing the cable attachment bracket from unexpectedly moving out of position without the intent of the driver of the vehicle when the shifter is electronically actuating the transmission.